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From "Jack Krupansky" <j...@basetechnology.com>
Subject Re: Query Performance
Date Sun, 28 Jul 2013 21:44:07 GMT
start is a window into the sorted, matched documents.

So, whether the second query matches a lot less documents, and hence has 
less to sort, depends once again on where X lies in the distribution of 
documents. If X if the first term in the field, the second query would match 
all documents (except for the first since you used "{" rather than "["). 
But, the query itself might be slower than a *:* query depending on exactly 
how Lucene evaluates range queries.

-- Jack Krupansky

-----Original Message----- 
From: Furkan KAMACI
Sent: Sunday, July 28, 2013 5:34 PM
To: solr-user@lucene.apache.org
Subject: Re: Query Performance

Actually I have to rewrite my question:

Query 1:

q=*:*&rows=row_count&sort=id asc&start=X

and

Query2:

q={X TO *}&rows=row_count&sort=id asc&start=0



2013/7/29 Jack Krupansky <jack@basetechnology.com>

> The second query excludes documents matched by [* TO X], while the first
> query matches all documents.
>
> Relative performance will depend on relative match count and the sort time
> on the matched documents. Sorting will likely be the dominant factor - for
> equal number of documents. So, it depends on whether starting with X
> excludes or includes the majority of documents, relative to whatever
> row_count might be.
>
> Generally, you should only sort a small number of documents/results.
>
> Or, consider DocValues since they are designed for sorting.
>
> -- Jack Krupansky
>
> -----Original Message----- From: Furkan KAMACI
> Sent: Sunday, July 28, 2013 5:06 PM
> To: solr-user@lucene.apache.org
> Subject: Query Performance
>
>
> What is the difference between:
>
> q=*:*&rows=row_count&sort=id asc
>
> and
>
> q={X TO *}&rows=row_count&sort=id asc
>
> Does the first one trys to get all the documents but cut the result or 
> they
> are same or...? What happens at underlying process of Solr for that two
> queries?
> 


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